NET ASSIMILATION RATE AND YIELD OF Physalis UNDER CULTIVATION IN TWO LOCALITIES

Abstract

The yield of a crop is determined by its capacity to accumulate dry matter in the organs destined for harvest; thus, the analysis of growth is important in cultivated species. In this study the net assimilation rate, relative growth rate and fruit yield were evaluated in eight wild populations of Physalis under cultivation in two contrasting locations. The experimental design was complete randomized blocks with factorial arrangement. The 16 treatments resulted from the combinations of two localities and eight genotypes. The data were analyzed with analysis of variance and treatments means were compared with the Tukey test (P ≤ 0.05). To understand the relationship between fruit yield and net assimilation rate and relative growth rate, as evaluated from transplant to fruiting, a simple linear regression was calculated. Results indicated that yield of husk tomato (Physalis philadelphica Lam.) was higher in Texcoco, State of Mexico (722.1 g m^-2) than that in Tlaquiltenango, Morelos (370.9 g m^-2) due to a larger leaf area per plant (128.9 dm²), net assimilation rate (TAN) and relative growth rate (TCR), with averages of 1.58 g dm² d^-1 and 0.09 g g^-1 d^-1, respectively. The average yield of P. philadelphica was 1473.7 g m^-2, higher than that of the other genotypes evaluated due to its greater leaf area per plant (501.3 dm²), net assimilation rate (1.72 g dm² d^-1) and relative growth rate 0.096 g g^-1 d^-1). Wild materials proved to be more productive, and P. solanacea has the potential to be planted for its high yield (478.8 g m^-2). Regression equations REND = 769.7 (TAN₄) - 410.7 (R² = 0.51*) and REND = 46427 (TCR₄) - 3206.3 (R² = 0.83**) demonstrated that net assimilation rate and the relative growth rate positively affected fruit yield.