INFLUENCE OF TEMPERATURE ON THE YIELD AND QUALITY OF THREE STRAWBERRY ( Fragaria * anannasa Duch) CULTIVARS

ABSTRACT

The influence of temperature on yield and quality of three Japanese strawberry (Fragaria x anannasa Duch) cultivars („Sachinoka‟, „Benihoppe‟ and „Tochiotome‟) were studied between March and August, 2011 in a screen house at Tokyo University of Agriculture and Technology, Japan. Completely Randomised Design was used with eight (8) replications each of the cultivars. One set of treatment comprising of the three cultivars were set as control and the other treatment was set under a thin film of shade. Yield parameters taken included fruit length, fruit weight, fruit width and number of fruit harvested per plant. Quality parameters taken were fruit colour and fruit firmness. Few vegetative growth parameters were also recorded and these included leaf length and leaf area. The optimum day/ night temperature for fruit development, fruit length, fruit width and fruit weight was 26/14 ºC, which occurred in the month May. However, the above parameters reduced as temperature increased throughout the study period. Further, fruit firmness decreased as the temperature increased throughout the study period. Fruit surface colour L, which indicates „lightness of colour‟ became darker and greater in pigment intensity as temperature increased to 34/23 ºC in July. Increasing growth temperatures resulted in smaller leaf area whiles leaf length increased. Chlorophyll content of leaves and light interception by plants in screen house also increased as the iii growth temperature increased. Increasing growth temperatures of the environment resulted in decreased fruit quality including soluble solids. However, sugar-acid ratio, titratable acids and pH varied among the cultivars indicating that these qualities may be heritable traits as they were less influenced by the environment.