Abstract
To screen and test the performance of early bulking high yielding potato genotypes
for potato based cropping patterns of North-Western Bangladesh, four field
experiments were conducted at Regional Agricultural Research Station, Burirhat,
Rangpur, during 2014 to 2018. Early bulking behavior of twenty six potato
genotypes were observed in the first experiment. The second experiment was
designed by allocating five planting dates viz. 1 October; 8 October, 15 October, 22
October and 29 October and three potato genotypes viz. 7 Alu, Sagitta and Courage
were selected based on the results of the first experiment. The third experiment
examined the performance of these three genotypes under varying tuber sizes and
spacings. The tuber sizes were small (20-35 mm), medium (35-45 mm) and large
(45-55 mm) and four spacings were 65 cm × 30 cm, 60 cm × 25 cm, 55 cm × 20 cm
and 50 cm × 15 cm. In experiment four, twelve improved potato-based cropping
patterns were tested along with one existing pattern to ascertain suitable
genotype(s) in terms of productivity. In the first experiment, Marketable tuber yield
of twenty-six genotypes at 55 days after planting (DAP) ranged from 7.37 to 16.53 t
ha-1. The highest marketable tuber yield and skin colour was recorded in 7 Alu
(16.53 t ha-¹) followed by Sagitta (15.02 t ha-1) and Courage. Hence, these three
genotypes were selected for the second experiment. In the second experiment, total
tuber yield and marketable tuber yield obtained from the three genotypes were
highest and these gave the highest economic benefit when planted on 1 October
and harvested at 55 DAP, because of high market price in the early season. In the
third experiment, total tuber yield and marketable tuber yield at 55 DAP became
prominent in 7 Alu and Sagitta planted with medium and large seed tubers using
spacing of 50 cm × 15 cm. Considering the above findings, the fourth experiment
was set in the field in the year 2017-18 to observe the fitness of the genotypes in
different patterns. At 55 DAP, the genotypes 7 Alu and Sagitta yielded 17.70-19.24 t
ha-1 and 16.45-17.20 t ha¹, respectively in different patterns under investigation.
The highest potato equivalent yield (PEY) of 95.37 t ha1 was recorded in the
improved pattern 7 Alu-Cardinal-Mungbean-Lalshak -T. Aman rice and the lowest
of 45.10 t ha-¹ one was found in the existing pattern Potato-Boro rice-T. Aman rice.
PEY increased by 43.84 to 111.46% in the improved patterns over the existing one.
A marked increase in total productivity was observed in the improved early
bulking potato-based cropping patterns compared to the existing pattern. Thus, 7
Alu-Garden Pea-Lal shak-T. Aus rice-T. Aman rice pattern would be the most
suitable pattern for the farmers of North-Western Bangladesh for achieving higher
total productivity and profitability. For double potato growing areas 7 AluCardinal-Mungbean-Lal shak-T. Aman rice and 7 Alu-Wheat-Mungbean-Lal shakT. Aman rice cropping patterns would be more productive and hence profitable for the farmers of North-Western Bangladesh.