Fig. 2. Rough seedlings planted at Pun- jab Agricultural University. They will be used for rootstocks for Kin- now mandarin.

Fig. 1. Map of showing New Delhi and the two regions which were visited, and Li v i n g Nagpur. uanglongbing (HLB) is now present Hthroughout Florida with HLB citrus and everyone agrees that strategies must be found to man- age this serious disease to remain in India profitable. Historically, the disease By Ron Brlansky, Megh Singh and Michael Rogers probably has been in India since the early 1900s. Reports of a decline and India is a large country, so Punjab Agricultural University in the dieback of citrus was first reported in two major production areas in city of Ludhiana (see map Fig. 1). the state of Punjab. The decline was the northwest (Punjab) and in the The university is one of the premier originally thought to be psyllid dam- central (Nagpur) regions of India agriculture universities in India and age; however, fruit with an “insipid” were visited (Fig. 1). many students have come from there to flavor were described. Singh, being native to India, designed do graduate work at the University of Following conversations concerning the two-week trip. After a 16-hour Florida and at CREC. HLB in India, Ron Brlansky, Michael flight from Newark, N.J., the three We visited the faculty in plant path- Rogers and Megh Singh developed a CREC scientists arrived in New Delhi, ology, entomology and horticulture trip there in October 2008 to investi- India. After an overnight stay in New and were hosted by the president of the gate and how citrus Delhi, the group left the next morning university, M.S. Kang, who was at one growers and researchers manage HLB. via car, to drive to the state of Punjab, time a faculty member at the University where some of the of Florida’s Everglades Research and best crops are grown Education Center. Both Rogers and Br- on some of the best lansky presented short seminars on the agricultural land. purpose of our visit and the ongoing We went first to problem of HLB in Florida. We saw some citrus propagation programs and learned that the primary rootstock used in India was (Fig. 2). We left Ludhiana and drove to Hoshiarpur to see groves of Kinnow mandarin on rough lemon rootstock. This mandarin is the primary citrus grown in this area. We were accompa- nied by H. S. Dhaliwal, a horticulturist at Punjab Agriculture University, and visited the groves of B. S. Ahluwalia. The Kinnow mandarin trees were Fig. 3. Large Kinnow mandarin tree on rough lemon rootstock in the state of Punjab impressive in size and the fruit yield and near the city of Hoshiarpur. and size was good (see Fig. 3). On CITRUS INDUSTRY • October 2009 Kinnow mandarin and the rootstock NAGPUR was rough lemon. We were asked to We flew from New Delhi to Nagpur present talks on the HLB research in the central part of India. Nagpur is and management practices in Florida. the location of the National Research Presentations were made to a group of Center for Citrus, which is the principal approximately 300 citrus growers from location for citrus research in India. We the region. were greeted by the center director, V. We then went to the Sharda groves J. Shivankar, and taken on a tour of the and viewed their citrus production and research center groves. There we saw answered many questions posed by the rootstock and scion trials and other growers. While in Hoshiarpur we saw citrus collections. We saw many trees some as well as HLB. In with HLB and, even though they were Fig. 4. HLB blotchy mottle symptoms on addition, we saw a lot of Phytophthora just emerging from the hottest months Kinnow mandarin in Hoshiarpur. root and foot rot. This was mainly due of the year, psyllid populations were close inspection of the trees, we could to the fact that the growers commonly already high in numbers. Phytophthora see some blotchy mottle symptoms grow other crops between the rows and foot rot was very evident and again indicative of HLB (Fig. 4); however use cultivation rather than chemicals was due to tillage practices between Ahluwalia said that even with HLB, the to control weeds. Weeds around the rows and weed control near trees trees produced well. trunks of trees are cut with machetes was with machetes. Irrigation was by As with most mandarins, extra foliar and often resulted in trunk damage. flooding the grove. We were told that Irrigation was by flooding, which en- nutritional sprays were applied to main- Phytophthora foot rot was their main hanced infection by Phytophthora. tain fruit yield and size, and probably problem. We then visited a large citrus nurs- attribute to the masking of the blotchy We had a discussion on our HLB ery and again found plant production mottle leaf symptoms. In this grove, programs with the scientists at the re- on the ground rather than on benches. search center and the problem of HLB tree age approached 25 years, which is Plants were housed in shade houses; probably unusual for trees in an area in India. Rogers and entomologist C. however, they N. Rao had meaningful where HLB is prevalent. Evidence of were not psyllid- Phytophthora foot and root rot in some discussion on psyllid proof and psyllid management in India. trees was noted. Soil type was a clay feeding damage Brlansky visited many loam and irrigation is by flooding. was observed. We of the plant pathology In addition, we saw some 2-3-year- saw the propa- research labs and spent old Hamlin trees on rough lemon gation of rough time with Dilip Ghosh, rootstock. These trees were part of a lemon rootstock who spent a three-month program in conjunction with Pepsico from seed and technical training study (Tropicana) to introduce other sweet visited the trees at the University of Flor- in this region. The where the seed ida’s Citrus Research trees were infected with HLB, but were originated. The and Education Center growing. However, no fruit set was seen. rough lemon trees (CREC). Brlansky also In another, smaller grove, we did were large and visited with Ashish Das, see some reduction in fruit size and growing well and who works on HLB yield in Kinnow mandarin; however, producing abun- diagnosis. we learned that the grower didn’t apply dant fruit for the Das accompanied the recommended foliar fertilizer ap- seed. They were us on visits to multiple plications due to the high cost and low HLB-infected grove sites around Nag- fruit return. At this location, we did with symptoms pur where we saw HLB see some citrus canker, but little fruit that we have seen in epidemic propor- infection and no fruit drop. Tempera- in our greenhouse Fig. 5. HLB “yellow shoot” symptoms tions. The symptoms on Nagpur mandarin on rough lemon tures can be relatively high (up to 110 inoculation work of “yellow shoot” or with HLB in rootstock near the National Research huanglongbing were very degrees F) prior to the rainy monsoon Center for Citrus in Nagpur, India. season; however, while we were there, Florida. In ad- obvious on Nagpur (Fig. they were entering into the cooler, drier dition, we found 5) and canopy the psyllids actively time of the year. blotchy mottle feeding on numer- We next visited with a gathering of symptoms were ous other citrus farmers from the region and discussed very apparent trees. the situation with HLB. They admit- (Photo 6). The We ended our main cultivars ted that HLB was a problem, but also stay in Punjab and said that Phytophthora root and foot rot in this region the next day began are Nagpur and were significant problems as well. a long trip back to We left Hoshiarpur and went back Kinnnow, all New Delhi. The on rough lemon to Ludhiana and then on to Abohar. trip took us through rootstock. Abohar is very close to the many states of We saw border. India and eventually an open field Next we visited Sharda Agricul- through the town of Fig. 6. Close-up of HLB blotchy mottle nursery where tural Farms owned by Mahesh Sharda. Agra, home of the symptoms on Nagpur mandarin leaves rough lemon Again, the major grown was Taj Mahal. inside the canopy. was grown CITRUS INDUSTRY • October 2009 Institute where a number of Phytophthora root and foot rot is a excellent plant pathologists major problem, but control by cultural and entomologists work and and chemical means can be accom- train students in agriculture plished. Psyllid control is variable in research. Rogers and Brlan- the areas that we visited, and it is very sky both presented seminars difficult to obtain satisfactory pest on their research on HLB and reduction. on what we had seen on our Plant materials grown in nurseries trip through the two citrus and in open field nurseries are probably production areas in India. HLB infected prior to planting. They discussed research col- Use of the vigorous rootstock rough laborations on HLB and other lemon may offset some of the reduction important citrus problems. in yields, especially on cultivars such as Kinnow and Nagpur. Fig. 7. Nagpur mandarin fruit recently harvested SUMMARY showing the reduction in fruit size. The camera All of these production problems lens cap in the photo is 2 1/4 inches in diameter. In conclusion, we found need further study in India. We plan that India is living with HLB; to continue collaborative work, begin- and grafted with the scion of choice. however, it is continually taking a toll ning with visits of Indian scientists The rough lemon had early symptoms on fruit production. Fruit size and yield to CREC (two visits are planned) and of HLB; thus the plants were already of Kinnow mandarin on rough lemon look forward to other cooperative infected. At one location, harvest- rootstock in Punjab was minimal. With interactions with other Indian citrus ing of Nagpur was under way and the proper cultural methods and psyllid industry contacts. reduction in fruit size was clearly seen control, the cultivar seemed to tolerate Ron Brlansky, Megh Singh and Michael (Photo 7). We ended our trip to Nagpur HLB; however, other cultivars such as Rogers work for the University of Florida’s and flew back to New Delhi. Nagpur were obviously severely af- Citrus Research and Education Center, While in New Delhi, we visited fected. The production of new cultivars Lake Alfred. the Indian Agricultural Research such as Hamlin is yet to be determined.

CITRUS INDUSTRY • October 2009