EVALUATION OF RESISTANCE TO Selenothrips rubrocinctus Giard AMONG VARIOUS Psidium GENOTYPES BASED ON SOME FRUIT PARAMETERS A THESIS SUBMITTED TO THE GRADUATE DIVISION OF THE UNIVERSITY OF HAWAII IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN HORTICULTURE AUGUST 1980 By Steven Leroy Foss Thesis Committee Henry Y. Nakasone, Chairman Roy K. Nishimoto Toshiyuki Nishida We certify that we have read this thesis and that in our opinion it is satisfactory in scope and quality as a thesis for the degree of Master of Science in Horticulture. THESIS COMMITTEE r "Chairman ACKNOWLEDGEMENTS The author wishes to extend his appreciation to Dr. C. Murdoch for his assistance and use of the turf-grass laboratory facilities. Special acknowledgement goes to Dr. J. Deputy of the UH-Botany Department for providing the methodology and laboratory facilities used in the elemental analysis of guava fruits and Dr. T. Fujimoto for sharing his expertise in leaf analysis. He also wishes to thank Ms. Natalie Nagaji for her willingness and efforts in typing the final manuscript. Finally, he thanks his family and friends for their support during this study. iv TABLE OF CONTENTS Page ACKNOWLEDGEMENTS ............................................. iii LIST OF T A B L E S ............................................... vi LIST OF I L L U S T R A T I O N S ...................................... x INTRODUCTION ................................................. 1 LITERATURE REVIEW ........................................... 5 G u a v a ................................................... 5 Red-banded thrips (RBT) ................................ 11 Insect Resistance ...................................... 28 MATERIALS AND METHODS ...................................... 37 Comparisons of russeted and undamaged fruits from clone 1 5 7 ........................................ 37 Evaluation of RBT preference among various Psidium genotypes and the relationship of fruit parameters to preference .............................. 38 Influence of K fertilization on RBT preference for clones 143, 157, 180 and 'Beaumont' and the relationship of fruit parameters to p r e f e r e n c e ............................................. 47 Effect of K levels on clones 180, 157 and 'Beaumont' grown in containers and the relationship of fruit parameters to preference .... 49 Statistical analyses .................................. 50 RESULTS AND DISCUSSION ...................................... 53 Comparisons of russeted and undamaged fruits from clone 1 5 7 ........................................ 53 Evaluation of preference among various Psidium genotypes and the relationship of fruit parameters to preference................................ 57 V TABLE OF CONTENTS (Continued) Page Influence of K fertilization on RBT preference for clones 143, 157, 180 and 'Beaumont' and the relationship of fruit parameters to p r e f e r e n c e ............................................. 82 Effect of K levels on clones 180, 157 and 'Beaumont' grown in containers and the relationship of fruit parameters to preference .... 95 SUMMARY AND CONCLUSIONS ...................................... 110 APPENDIX ................................................ 114 LITERATURE CITED 116 vi LIST OF TABLES TABLE Page 1 Comparison of russeted and undamaged fruits from clone 1 5 7 ........................................... 53 2 Mean comparison of % RBT response and insect rating among six replicated Psidium genotypes over 10 dates in 1979 58 3 Mean comparison of fruit length, width, moisture content, soluble solids and firmness for six replicated Psidium genotypes over 10 dates in 1979 ......................................... 59 4 Percent nutrient content of nitrogen, phosphorus, potassium, calcium and magnesium in guava fruits sampled from six replicated Psidium genotypes over five pairs of consecutive dates in 1979 60 5 Comparison of % RBT response and insect rating among 14 Psidium genotypes over 10 dates in 1979 ...................................... 61 6 Comparison of fruit length, width, moisture content, soluble solids and firmness of guava fruits from 14 Psidium genotypes sampled over 10 dates in 1979 64 7 Percent nutrient content of nitrogen, phosphorus, potassium, calcium and magnesium in guava fruits sampled from 14 Psidium genotypes over five pairs of consecutive dates in 1979 65 8 Linear regression equations, coefficients of determination (R2) and correlation coefficients (r) between preference and 10 fruit parameters on the combined analysis of 14 Psidium genotypes . 69 9 Multiple regression equations and coefficients of determination (R2) between preference and 10 fruit parameters on the combined analysis of 14 Psidium genotypes .............................. 72 vii LIST OF TABLES (Continued) TABLE Page 10 Sequential F-test of regression analysis for the fruit parameters................................ 73 11 Linear regression equations, coefficients of determination (R2) and correlation coefficients (r) between preference and the best fruit parameter for each of the three Psidium groups ......................................... 78 12 Comparison of % RBT response and insect rating for fruits from four clones sampled over seven dates ...................................... 83 13 Comparison of % RBT response and insect rating for guava fruits sampled over seven dates from trees treated at two K l e v e l s ............. 83 14 Comparison of % RBT response and insect rating for four guava clones grown at two K levels in the f i e l d ............................ 84 15 Length, width, moisture content, soluble solids and firmness of fruits sampled on seven dates from four guava c l o n e s ................... 85 16 Length, width, moisture content, soluble solids and firmness of fruits sampled on seven dates from guava trees treated with two K l e v e l s .......................................... 85 17 Percent nutrient content of nitrogen, phosphorus, potassium, calcium and magnesium of fruits sampled on seven dates from four guava clones ........................................ 86 18 Percent nutrient content of nitrogen, phosphorus, potassium, calcium and magnesium of fruits sampled on seven dates from guava trees treated with two K l e v e l s ..................... 86 19 Changes in the mean parameter values for guava fruits sampled during two periods in 1979 S7 Vlll LIST OF TABLES (Continued) TABLE Page 20 Linear regression equations and coefficients of determination (R ) between preference and ten fruit parameters for four guava clones treated with two K levels ................................ 89 21 Comparison of nitrogen and potassium content in leaf tissue taken from four guava clones treated with two K levels on nine d a t e s .............................................. 90 22 Percent nutrient content of nitrogen and potassium in leaves from four guava clones taken on nine dates of sa m p l i n g ........................... 93 23 Percent nutrient content of nitrogen and potassium in leaves from two K levels taken on nine dates of s a m p l i n g ..................... 93 24 Interacting effects of four guava clones and two K levels over nine dates of sampling for percent nutrient content of nitrogen and potassium in leaves ............................ 94 25 Comparison of % RBT response and insect rating for fruits from three guava clones grown in containers ................................ 96 26 Comparison of % RBT response and insect rating for guava fruits from plants grown at three K levels .................................. 96 27 Comparison of % RBT response and insect rating for fruits from guava clones grown at three K levels in containers..................... 97 28 Length, width, moisture content, soluble solids and firmness of fruits from three guava clones grown in containers ................... 98 29 Length, width, moisture content, soluble solids and firmness of fruits from guava plants grown at three K levels ..................... 98 ix LIST OF TABLES (Continued) TABLE Page 30 Percent nutrient content of nitrogen, phosphorus, potassium, calcium and magnesium of guava fruits sampled from four guava clones grown in containers ............................. 99 31 Percent nutrient content of nitrogen, phosphorus, potassium, calcium and magnesium of fruits sampled from guava plants at three K levels .............................................. 99 32 Length, width, moisture content, soluble solids and firmness of fruits sampled from three guava clones grown at three K levels in c o n t a i n e r s ...................................... 101 33 Percent nutrient content of nitrogen, phosphorus, potassium, calcium and magnesium of fruits from three guava clones grown at three K levels in containers....................... 103 34 Linear regression equations, coefficients of determination (R ) and correlation coefficients (r) between PREF and 10 fruit parameters on the combined analysis of three guava clones .................................. 105 X LIST OF ILLUSTRATIONS PLATE Figure Page I 1 Cacao (Theobroma cacao)................... 13 2 Cashew (Anacardium occidentale)........... 13 3 Distal primary subvascular distribution of the RBT on leaves from the false kamani (Terminalia catappa) .......... 13 4 Mango (Mangifera indica) .................. 13 5 RBT damage on the fruit of the strawberry guava (Psidium cattleianum)............... 13 6 Azonal distribution of the RBT on leaves from the false kamani (Terminalia catappa) ..................... 13 II 7 Immature and an