How different hermetic bag brands and maize varieties affect grain damage and loss during smallholder farmer storage

Susceptibility studies keep farmers informed, and enhance breeding programmes' testing against infestation and damage by stored product pests. Therefore, the susceptibility of 20 elite maize varieties toSitophilus zeamaisinfestation was investigated in the laboratory at 32.7 °C ambient temperature and 70.4% relative humidity. The varieties tested were obtained from the Maize Breeding Units of International Institute of Tropical Agriculture (IITA), and Institute of Agricultural Research and Training (IAR&T), both in Ibadan, Nigeria. Susceptibility was assessed, using as indices, weevil mortality and survival rates, percentage grain damage, percentage grain weight loss, weight of grain powder, weevil development time, and number of emerged adults. The susceptibility index was determined post-infestation at 56 days using Dobie's formula and at 90 days from a new formula derived from Dobie's formula. Susceptible varieties produced significantly (P≤ 0.05) high numbers of F1and F2progeny, and had significantly (P≤ 0.05) low weevil mortality and early first weevil emergence. Grain damage and loss increased with storage duration. There was no visible damage to varieties 2000SYNEE-WSTR and TZBRELD3C5 at 56 days post-infestation. At 90 days, the two varieties had the lowest percentage grain damage, percentage weight loss, and weight of grain powder. The index of susceptibility at F2progeny showed that the resistant varieties decreased in number from 17 (85%) to 13 (65%) and the moderately resistant varieties increased from 2 (10%) to 6 (30%). This suggests the effect of prolonged storage duration on the inherent ability of varieties to resist weevil attack. Variety PVASYN3F2 was susceptible. The factors conferring high resistance to 2000SYNEE-WSTR and TZBRELD3C5 should be investigated. They should be promoted to controlS. zeamaisinfestation and damage in stored maize.

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Resistance of Some Hybrid Maize (Zea mays L.) to Damage by Maize Weevil Sitophilus zeamais (Motsch.) (Coleoptera: Curculionidae) and Larger Grain Borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae)

Nigeria Journal of Entomology ◽

10.36108/nje/9102/53.01.50 ◽

2019 ◽

Vol 35 (1) ◽

pp. 45-59

Author(s):

T. J Adebowale ◽

A. A Osipitan

Keyword(s):

Adult Mortality ◽

Sitophilus Zeamais ◽

Control Measures ◽

Prostephanus Truncatus ◽

Maize Weevil ◽

Grain Damage ◽

Maize Varieties ◽

Grain Dust ◽

Hybrid Maize ◽

Moderately Resistant

Damage to stored maize grains by Sitophilus zeamais and Prostephanus truncatus is enormous and could be total if the insects are not controlled timely and appropriately. Control of the insects with host plant resistance has advantages over other control measures because of its lasting effect, friendliness to the environment and safety to natural enemies among others. This study assessed host resistance of 11 maize varieties to infestation and damage by S. zeamais and P. truncatus. One hundred gram maize grains each of the maize varieties were weighed into 250 cm3 glass jars and separately infested with twenty, 1-5 days old S. zeamais or P. truncatus. Percentage grain damage, weight loss, adult mortality, grain dust and number of insects were determined and integrated to define the resistance of the maize varieties to the insects. Eight of the 11 maize varieties were either resistant or moderately resistant to damage by S. zeamais and P. truncatus, while three were susceptible. The basis of resistance is antibiosis conferred by the ash, carbohydrate and fat content of the maize grains. The resistance varieties could be planted to mitigate infestation and damage by the insects. The factors conferring resistance can be used as environmentally friendly source of resistance to breed maize grains for resistance to the insects.

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IMPLEMENTATION OF LOW-TRAUMATIC TECHNOLOGY OF GRAIN SEPARATION FROM A WHEAT EAR: RESULTS OF THE PILOT STUDIES

STATE AND DEVELOPMENT PROSPECTS OF AGRIBUSINESS. In the frame of the XXIII Agribusiness Forum of the South of Russia and the Exhibition «Interagromash» Volume 1 ◽

10.23947/interagro.2020.1.211-214 ◽

2020 ◽

Author(s):

V.I. Pakhomov ◽

◽

S.V. Braginets ◽

O.N. Bakhchevnikov ◽

A.I. Rukhlyada ◽

...

Keyword(s):

Separation Process ◽

Experimental Device ◽

Cereal Crops ◽

Pilot Studies ◽

Traditional Technology ◽

Air Jet ◽

Cereal Breeding ◽

Grain Damage ◽

Partial Abrasion

Low-traumatic technology of grain separation from an ear is developed. It consists in influence of an air jet on an ear.It leads to rolling of an ear on a surface of the threshing device concave and causes its partial abrasion which is followed by grains separation. Process of wheat ears low-traumatic threshing in the experimental device yields satisfactory results, provides reduces grain endosperm damage on 10-12% in comparison with traditional technology. Germ of grain damage decreases by 5%.Crushing of grain made no more than 0,5%. Use of the developed technology of the low-traumatic threshing will allow to reduce grain damage of cereal crops in case of the harvesting. It is important by cereal breeding.

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