Correlation study in growth parameters of Pongamia (Pongamia pinnata) and physiological parameters of black gram (Vigna mungo (L.) Hepper) in agroforestry system

Abstract

The present investigation was conducted to study the tree crop interaction considering the Pongamia (Pongamia
pinnata) tree morphological characteristics and physiological parameters of black gram (Vigna mungo (L.) Hepper) in
agroforestry system. The experiment was conducted during kharif 2019-20 and 2020-21 in "T" block, Agroforestry
experimental fields of University of Agricultural Sciences, Dharwad campus which is located at 15° 26' North latitude and
75° 0' East longitude, with an elevation (altitude) of 678 m above mean sea level. Pongamia pinnata provenance's growth
and volume observations were recorded. They included tree height, tree girth, canopy cover and number of branches etc.
Two years pooled data recorded maximum values in treatment (T1) RAK-1 (Rahuri Karanja-1) + black gram followed by
(T9) RAK-9 + black gram which is on par with (T6) RAK-7 + black gram. Lowest values recorded in (T8) RAK-9 + black
gram which is on par with (T4) RAK-4 + black gram. Whereas the growth parameters of black gram like leaf area duration
(LAD), absolute growth rate (AGR), crop growth rate (CGR) and dry matter accumulation recorded under Pongamia
provenances which showed opposite trend because of the fluctuations of light and mutual shading of the crops within or in
between rows, frequent overcast due to clouds as a common phenomenon during tropical and sub-tropical monsoons
causing regular fluctuation of sunlight. The treatment (T11) sole crop showed the maximum value, followed by (T8) RAK-
9 + black gram and (T4) RAK4 + black gram and lowest value was recorded at (T1) RAK-1 + black gram treatment. Sole
legumes recorded maximum AGR. CGR, LAD and dry matter accumulation were also found to have highest significant
positive correlation with seed yield.