Naslov
Pests of stored oil crops

Autori
Lemić, Darija ; Žganec, Kristina ; Smiljčić, Anamarija ; Šupljika, Maja ; Gluščić, Paula ; Miklečić, Ivana ; Čačija, Maja

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
IOBC-WPRS Bulletin / Cook, Samantha M. ; Jedryczka, Malgorzata ; Juran, Ivan ; Truman, William - Darmstadt : IOBC-WPRS 2018, 2018, 43-44

Skup
17th meeting of the IOBC/WPRS Working Group "Integrated Control in Oilseed Crops"

Mjesto i datum
Zagreb, Hrvatska, 18.09.2018. - 20.09.2018

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
stored products, damage, storage, harmful entomofauna, Coleoptera, Lepidoptera, oilseeds

Sažetak
Oil crops, the source of oils for edible and multiple industrial uses hold an important position in the economy of developed as well as developing countries. Protecting stored oilseed crops from spoilage is an essential part of their production ; failure to do so may result in them being downgraded. Storing oilseeds is more difficult than storing cereal grains, as they are more susceptible to quality deterioration and have limited insect control options. The decision to store oilseeds requires a planned approach, careful management and a suitable storage system. The rate of quality deterioration in stored oilseeds depends on the quality of grain placed in storage and management of temperature, moisture content and insects. Studies on storage and insect pest control in oilseeds are relatively less when compared with cereal grains. Stored-product beetles often appear similar but have differing behaviour patterns and status as pests. It is important to determine which species are present before taking remedial action. The general recommended storage conditions for oil crops are below 25°C and below 7% moisture content but vary according to the oil content. Oilseeds as well as oilcakes/meals are rich in proteins and fats and hence are vulnerable to infestation by stored product pests, resulting in weight loss, deterioration in quality and flavour, contamination, mould growth and formation of toxins. In these commodities, Tribolium spp. among beetle pests and Ephestia cautella as well as Plodia interpunctella among moths are important. These insects tend to favour the top of the grain stack and around silo outlets. Under optimum breeding conditions of about 30°C, insects can complete their full life cycle in as little as four weeks. Reducing the grain temperature with aeration cooling plays a vital role in lengthening the insect breeding life cycle or in most cases stopping reproduction if cooled below 18°C. The aim of this research was to determine, during the period of six months, the abundance of harmful oilseeds entomofauna in the storage facilities of experimental station Šašinovečki Lug. Experimental station has an open type warehouse that allows better temperature regulation, airflow and ventilation in dry conditions. There is no temperature control in the storage facility, nor the relative humidity control. Stored oil crops were packed in one-toned bags made of polyester material. The oilseed grains were sampled using a special probe for grain sampling, which was "stacked" in a bag. The sampling was carried out from the bottom, the middle and the top of the sack, with a collective sample made of 1/3 of each layer sampled. The oilseeds (oilseed rape and turnip rape) were sampled once a month between 16 November 2017 and 15 April 2018. All together, both oil crops have been sampled six times, each time taking four sub-samples (total of 48 analyzed sub-samples, each weighing 250 g). During whole research period, physical properties (moisture, weight after sampling, weight after incubation and hectolitre mass) of oilseed rape and turnip rape were analyzed right after the sampling, and presence of entomofauna was observed. Each examined sample was then put on incubation for one month and the same procedure of analysis was preformed (physical properties and visual inspection for insects). Entomofauna found after both examinations was identified to species level using standard determination keys. The results of grain physical properties showed that, during the six month period, the oilseed rape grains had optimal average moisture (8-9%), while turnip rape average moisture was a bit lower (7-8%). In the first three samplings (November till January), the oilseed rape absolute weight increased by 10%, while the turnip rape weight increase was 20%, followed by weight loss in both oil crops till April. In overall, the oilseed rape absolute weight decreased by 12% and turnip rape by 15% when compared with the first sampling. Weight loss was also detected after the incubation period, with 5% of maximum weight loss for oilseed rape in February and 12% for turnip rape in December. The hectolitre mass values were standard for both oil crops. In total, 152 insects were detected immediately after the sampling and additional 25 specimens after the incubation period. All 177 insects belonged to the order Coleoptera. Of these, 94% were found in turnip rape samples. In oilseed rape, species Oryzaephilus surinamensis (L.) was detected both before and after the incubation, and the only other species was Cryptolestes ferrugineus (Steph.), found after incubation in February (both in low numbers). The most abundant species in turnip rape detected during all six months was Sitophilus granarius (L.) (81%), followed by Oryzaephilus surinamensis (13%). Other species found in turnip rape were Tribolium confusum J. du Val (3%), Gnatocerus cornutus (F.) (1.3%), Cryptolestes ferrugineus (Steph.) (0.7%) and Bruchus pisorum (L.) (0.7%). After incubation period, Sitophilus granarius and Oryzaephilus surinamensis were similarly abundant as after the sampling and were the only ones found. Although the analyzed oil crops had optimal average moisture and values of hectolitre mass, the presence of insect pests presumably had an effect on stored grains weight loss, which in the end causes poor grain quality and yield loss. The most abundant detected species Sitophilus granarius is a primary pest found mostly on stored cereals. It is considered the most common polyphagous insect in storehouse that prefers higher grain moisture. However, we found it in highest numbers on turnip rape, which had somewhat lower moisture than oilseed rape. Presumably, some other elements, like optimal temperature, were key factors contributing to this species successful development on turnip rape. Potentially, if these conditions change and become more favourable, we could expect to find this storage pest on oilseed rape as well, and also many other pests on different stored products. In order to ensure better storage conditions, it is necessary to disinfect the empty storage space, and upon receipt of the goods, by continuous sampling monitor the moisture and temperature of the products and the presence of harmful entomofauna, in order to react in a timely manner and thereby avoid greater losses.

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija)

POVEZANOST RADA