Planting date and plant density effects on flower abortion, fruit yield and seed quality of two varieties of chilli pepper (capsicum frutescens l.) in Ghana
Field and laboratory experiments were carried out between April 2014 and March 2015 to evaluate the effects of planting date and density on flower abortion, fruit yield and seed quality of two chilli varieties. The field trial was laid out in 2x3x3 factorial experiment in a Randomized Complete Block Design (RCBD) with 3 replications. The factors studied included two chilli varieties (Shito Adope and Legon-18); three planting dates (May 12, 2014; June 13, 2014; and September 29, 2014); and plant spacing at three levels (60 cm x 30 cm; 70 cm x 30 cm; 80 cm x 30 cm). The field study was conducted at the Crops Research Institute-Kwadaso Station, Kumasi, Ghana. Growth, yield and seed quality parameters were evaluated during the study period. Legon-18 exhibited higher performance than Shito Adope for parameters such as plant height (53.9 than 44.9), branch numbers (9.6 than 5.9), canopy width (42.67 than 39.30), fruit yield (3.33 than 2.86), number (73.40 than 60.21) and weight of seeds per fruit (0.37 than 0.33). In contrast, Shito Adope took fewer days to attain 50% flowering (30.07) and fruit set (33.97). Shito Adope also recorded higher flower drop (14.60). Dates of planting significantly affected growth and seed quality parameters with seedlings planted in May and June recording taller plants (52.6 and 54.9), more branches (8.8 and 7.7), wider canopies (44.3 and 43.9), and higher fruit yield (3.70 and 3.35). Early flowering and fruit set, higher germination and vigour percentages were attained during the same period; while flower drops were more prevalent during the first and third dates of sowing with values of 14.90 and 15.80, respectively. Higher seed yields were recorded during the September planting. Plant density showed no iv significant effect on all parameters studied except plant height, with the widest spacing (80 x 30) recording the tallest heights (49.94). Six fungal species were identified; with Collectotrichum graminicola recording the highest pathogen incidence (282). Seeds planted in May, 2014 recorded the highest fungal pathogens occurrence. The results indicate that for quality seed production, chilli should be cultivated during periods with moderate rainfall to avoid higher disease infection; however, periods with extremely high temperatures should also be avoided as they tends to increase the rate of flower drop.
A thesis submitted to The School Of Graduate Studies, Kwame Nkrumah University Of Science And Technology in partial fulfilment of the requirements for the degree of Master of Philosophy In Seed Science and Technology, 2015