The Kara Mandarin tangerine-type, late spring of excellent eating quality is promising

James W. Cameron and Robert K. Soost

The Kara mandarin is a tangerine-type erably larger than the and Clemen- fruit, which was first described in tine tangerines when grown in the same 1935. Its parents were the Satsuma man- location. The Kara is moderately seedy, darin and the King-probably a . but scarcely more so than the Dancy and Because of its high quality, additional . Early in its season it is rather the Kara mandarin, as grown at Riverside. studies were made in 1952 on the be- high in acid but it is also high in solids About natural size. havior of the Kara. which are usually maintained over a rela- The fruit of the Kara is rich and of tively long period-three to four months pleasant flavor with an attractive, deep- at Riverside. Kara throughout the season. The lowest pulp color. At Riverside it is usu- Between 1930 and 1932,12 Kara trees, value, l33%, was from a tree on Rough ally edible from about March 1 to late one or more on each of several rootstocks, stock. The acid percentage was still June, its season extending somewhat be- were planted at the Citrus Experiment high-about 2%-in the assays made on yond that of the Washington Navel. It Station. At about the same time a few February 13, but it was generally satis- peels well, is usable by segments, and until trees were set in co-operative planting factory at the later dates. The high value after its midseason is satisfactory for in the Coachella Valley near Indio and of 1.71% shown for the March 31 sam- juicing. In April or May it begins to be- a few were planted in Tulare County near pling occurred from only one tree. This come puffy but is excellent for eating out Porterville and in Kern County near fruit sample also had 16.3% soluble of hand. The fruit is not inclined to gran- Delano. Data taken from time to time solids so that the so1ids:acid ratio was ulate and at Riverside adheres well to have indicated promise for the Kara at still 9.5:l. the tree. The rind color is a deep orange- Riverside and to some extent at Indio. At the Indio location the assays made yellow. The rind is more brittle than that The behavior of the variety in other areas on February 28 showed high juice con- of oranges and the fruit requires care in is still uncertain. tent, high solids, and an acid percentage handling and shipping. Juice analyses made in 1952 of fruit which gave about a 1O:l ratio. In some In recent small-scalemarketing tests at from trees of the 1930-1932 plantinge years the acid is considerably lower in Los Angeles and New York, Kara fruit together with one assay from two 7-year- the Coachella Valley by this date, but the was sold at 104 to 256 per pound, whole- old trees near Piru, in Ventura County- Kara is definitely a late season fruit in sale. Only a small quantity of the fruit are summarized in the table on this page. that area and is not ready for use at which brought these prices was available For the analyses from the Riverside - Christmas. Its season there is rather short at the auctions; the market might not ing one tree on each of seven rootstocks and can be affected by a browning of the support such prices on large shipments. was included during the main season. stem end, which causes drop. When However, there is growing interest in Some variability was found in the juice grown in full sun the tree is more vigor- dessert types of citrus fruit for the late percentages of fruit from the Riverside ous and the fruit sweetens earlier than spring months, and the Kara-in the trees on any one date. This variability in the shade of date groves. Riverside area-is at its best when such was at least partly because of rootstock. At Delano, Porterville, and Piru the types are no longer in season in the com- As expected, there was a decrease in juice assays showed high solids, moderate to petitive regions. percentage at the end of the season, in low juice content, and rather high acid The Kara fruit is smaller than the June and July. The analyses show char- on the dates of sampling. Tree vigor was Washington Navel orange but is consid- acteristically high soluble solids for the good in all three locations. Yield and fruit size of the Kara were very good at Riverside in 1952. Yields Fruit Characters of the Kara Mandarin, 1952 Season of 12 trees ranged from 110 pounds to Range OP 341 pounds, with an average of 235 Location Date No. of trees1 % % % pounds. The low yield of 110 pounds was iuice solids acid from a tree in its off-bearing year, and Riverside Feb. 13 2 44.544.7 16.0-1 7.0 2.0 1-2.02 with a rather small top volume. Fruit Mar. 31 7 39.545.1 14.2-1 6.5 1.28-1.71 size, based on counts of several hundred Apr. 30 7 38.047.3 14.0-1 6.1 1.09-1 -29 from each of seven trees, averaged June 3 7 36.642.6 13.3-1 5.3 0.95-1.14 0.24 pound per fruit with a considerable July 8 2 34.4-39.8 13.8-1 5.0 0.91-0.92 range of smaller and larger sizes. The lndio Feb. 28 2 46.748.3 15.8-1 5.9 1.50-1.60 average size at Riverside over a period of several years is not as large-O.19 Delano Mar. 5 1 37.7 14.2 1.74 pound per fruit. Porterville Mar. 5 1 38.8 17.0 2.16 At Indio the fruit size is much larger. Piru Apr. 19 2 44.3 16.2 1.65 The average of nine samples obtained be- (mixed) tween 194.6 and 1952 from trees with medium or heavy crops was 0.37 pound trees were from 18 to 27 years of age except at Piru, 7 years. Rootstocks varied; some are dis- cussed in text. per fruit. The Kara is more nearly annual * One sample from each tree was assayed on each date. Usual sample sir0 was 20 fruits. Concluded on page 14

4 CALIFORNIA AGRICULTURE, JULY, 1953 AVOCADO The observations obtained during these In the group dormant 20 months, only studies, to the effect that Guatemalan two -out of 18-failed to grow. Continued from page 3 stocks are far more susceptible to what- New shoot growth was rapid. The aver- heim, Dickinson, Itzamna, Nabal, Hass, ever soil condition causes chlorosis, are age length of eight shoots of the group Challenge, and Taft-and 45 on six Mexi- limited in scope. Perhaps, as the root sys- dormant 20 months measured 1/2” on the can varieties-Ganter, Topa Topa, Duke, tems expand, trees now considered recov- fourth day, l%’ron the fifth, 1%’’ on Northrop, Mexicola, and Blake. Two trees ered may again become chlorotic or the sixth, and 2,/rr on the seventh day are on Waldin, a West Indian variety hitherto normal trees on both types of after watering was resumed. Seven days from . As in the first plot, all stocks may show the disease. after the first watering, vigorous plants Guatemalan seeds were of mixed origin, Whether the occurrence of chlorotic averaged 27 green shoots per plant. but seeds of the Mexican, except Ganter, and normal trees in some cases only about The greenhouse studies demonstrate came from single trees. The trees were 20’ apart and on the same rootstock va- that the initiation of summer dormancy propagated in the Subtropical Horticul- riety, is due to soil variation or genetic in pine bluegrass is associated with long ture Nursery at the University of Califor- differences in the rootstock seedlings is day-length and high temperatures. nia, Los Angeles. This nursery also fur- an open question. All that can be said Growth resumption, after extended nished trees for three additional plots. at present is that none of the 10 Guate- periods of dormancy, was obtained when In June, 1950, one year after planting, malan rootstock varieties used in the two the plants were subjected to relative cool- 7870-43 trees-of the trees on Guate- severely affected rootstock plots is im- ness and were watered. These conditions malan stocks showed chlorosis in varying mune. The number of trees on these stocks parallel those which normally prevail in degrees. Only one tree on Mexican stock varied from three to 18. This, and the the field when the plant enters and breaks was affected, but it soon recovered. The fact that in one plot 14 trees on a certain dormancy. two trees on West Indian stock remained variety showed 43% chlorosis and in the Horton M. Laude is Associate Professor of normal. As of September, 1951, a little other, eight trees on the same variety Agronomy, University of California, Davis. over a year after the disease appeared, showed loo%, stress the necessity for The above progress report is based on Re- 56%-24 trees-of the chlorotic trees more extensive information for valid search Project No. 1194A. were recovered or nearly so and 44%- comparison. 19 trees-were either dead or worthless. The loss on the basis of the 55 trees on F. F. Halma is Professor of Subtropical Horti- Guatemalan planted was 3576, as com- culture, University of California, Los Angeles, KARA pared to a 40% loss in the other plot. The late F. A. White was Farm Advisor, Santa As in the other plot, chlorotic trees are Barbara County, University of California, at Continued from page 4 the time the study reported here was made. scattered throughout the area and in some in bearing habit than most mandarins cases affected and normal trees on the The above progress report is based on Re- search Project No. 1458. and mandarin hybrids. In off years it same rootstock variety are side by side. usually produces at least light and often Five commercial trees-presumably on medium crops. The combination of heavy Mexican stock-which were planted ,in yield and large size on the Riverside trees place of severely chlorotic ones, so far DORMANCY in 1952 is resulting in light crops for have shown no symptoms of the disease. on most trees. Continued from page 10 1953 Also, of several hundred commercial In the Riverside planting the Kara has Fuerte trees on Mexican stock-planted day and greenhouse temperatures plants made vigorous trees on sweet orange, by the grower in 1948 and 1949 in the continued active growth, but those grown sour orange, , and Cleopatra same orchard in which the experimental under long-day and subjected to the high mandarin rootstocks. On trifoliate and plot is located-only three show chloro- temperature stresses ceased growth and rootstocks the trees are sis. Neither the old nor the young orange within one week after the last high tem- smaller and on Cunningham tree trees are chlorotic. perature exposure lost all or virtually all condition is poor. Fruit quality in 1952 Three additional plots were planted in visible green tissue. These plants were was best on the sweet orange, grapefruit, 1949 with trees from the same nursery and trifoliate stocks. which furnished the Fuerte trees for the dormant as they could be induced to re- sume growth under favorable conditions Some young plantings of Karas have plot in Orange County. Two of them are been established recently in the Riverside located in Ventura County and one in two to three months later. When pine bluegrass was permitted to area. One orchard of about 280 trees and Los Angeles County. Only three trees--- another of some 170 trees are just com- all in one plot in Ventura County-of grow in a warm greenhouse under natural day-length and without the high tempera- ing into bearing. A group of Karas top- about 200 on Guatemalan stocks planted worked on grapefruit in 1946 seem vigor- have shown chlorosis. None of a similar ture exposures, the plant was dormant by early June even though watered daily. ous, and averaged moderate crops in number on Mexican stock and three on 1952, with rather light crops set for 1953. West Indian are affected. This is similar to the field behavior. Two weeks after such dormancy had set in, Near Fullerton, in Orange County, a In the same orchard in which the three Kara topworked on a large grapefruit chlorotic Fuerte trees arelocated, 96 Hass watering was stopped on a series of these plants. The pots then remained dry on tree gave fruit of good size and color in and 54 Anaheim on Guatemalan as well 1952. In the Piru area of Ventura County as a similar number on Mexican and 11 greenhouse benches for 5, 7,11, 17, and 20 months. At the end ef each interval, a block of 86 three-year-old Karas is on West Indian stocks were planted in just beginning to bear. 1950. A year later 5% of the Hass and six pots were removed to a section of 10% of the Anaheim on Guatemalan greenhouse having daily maximum tem- James W. Cameron is Assistant Geneticist, stocks showed chlorosis. However, prac- peratures not exceeding 75’ F, and daily University of California, Riverside. tically all seem to be recovering. None watering was resumed. All plants of the Robert K. Soost is Assistant Geneticist, Uni- of the trees on Mexican or West Indian groups dormant 5, 7, 11, and 17 months versity of California, Riverside. H. B. Frost, Associate Plant Breeder, Emeri- are affected. Paradoxically, in the same resumed growth by the fifth day after tus, University of California, Riverside, intro- orchard eight of about 40 Mexican seed- the resumption of watering. The majority duced the Kara mandarin in 1935. lings planted by the grower showed the of these plants developed vigorous new The above progress report is based on Re- disorder a few months, then recovered. shoots 3/8“ to long on the fourth day. search Project No. 261.

14 CALIFORNIA AGRICULTURE, JULY, 1953