Potential of row intercropping of potato and soy bean on incidences and severity of common pests and diseases of potato under the changing climatic environment in Malawi

The potato production in Malawi is constrained however by a number of challenges among which
increased pests’ pressure ranks the most pressing. The crop pests (insect pests, diseases, nematodes and
weeds) interfere with potato growth and failure of crop to grow and produce by destruction of parts or
of total crops. Field experiments were carried out aimed at investigating management options for potato
for pests and diseases. The experiments were planted on research stations in the 2020/2021 cropping
season at Chitedze, Bvumbwe, Makoka, Bembeke, Mbawa and Tsangano Agricultural Research
Stations. There were 5 treatments laid in Randomized Complete Block Design (RCBD) replicated three
times on station following a rotation system. Pure stands of the legumes and the intercrops were
followed by a pure stand of potato in these subsequent years. Potato-soy bean intercrop followed 1:1,
2:1 and 3:1 alternate row. Pests and disease assessments were carried out on any pest/disease that was
observed. Average disease severity scores were recorded in three phases thus, at seedling, vegetative
and maturity. Plants from the net plot were scored individually using 0-9 disease scale while
assessment of severity of insect pests was estimated using visual rating scale as per the 1-5 scale.
Significant differences among the treatments were noted whereby low pests and disease severity scores
were observed in 1:1 potato-soy bean intercrop. The present study demonstrated that potato-soy bean
intercropping through 1:1 alternate row has potential role to suppress insect pests and diseases
infestation and infection respectively and consequently, increase potato yields. It is recommended that
farmers have to consider and use intercropping alongside induced resistances and biological control, as
the environmentally safe alternative methods for pests and disease control.