SHOOT DRY WEIGHT YIELD, BROMATOLOGICAL COMPOSITION, AND NUTRITIONAL STATUS OF ALFALFA CULTIVARS IN TROPICAL CONDITIONS

Improvement to animal genetics requires the supply of superior quality forage, such as alfalfa (Medicago sativa L.). Under tropical and subtropical conditions in Brazil, alfalfa cultivation has been restricted to the 'Crioula' cultivar, although studies have indicated that other cultivars have excellent potential of yield. The objective of this work was to evaluate the adaptation and longevity of 92 alfalfa cultivars to the tropical edaphoclimatic conditions by assessing shoot dry weight yield (SDWY), crude protein content (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and nutrient content in SDWY. The 'Crioula', 'P 105', 'Rio Grande', and 'Springfield' cultivars were the most promising owing to their higher yield and lower reduction in SDWY. Crude protein (CP) content varied among cultivars, with the highest value found in 'Pro INTA Lujan' (24.5%) and the lowest found in 'Pecos' (18.8%). NDF content ranged from 25.8% ('Key II') to 38.7% ('California 50'), while ADF content ranged from 16.4% ('F 708') to 24.8% ('Diamond'). Nutrient levels of all cultivars were within the levels considered appropriate for tropical conditions.

FRUGIVOROUS FLIES (Diptera: Tephritidae and Lonchaeidae) INTERACTIONS WITH PARASITOIDS AND NEW HOSTS

Fruits of two cultivars of guava, Psidium guajava L., (‘Tailandesa’ and ‘Kumagai’) and garlic passion fruit, Passiflora tenuifila Killip were collected to evaluate the infestation and co-infestation of frugivorous flies and the associated parasitoids and new hosts. Five species of Tephritoidea were recovered in Tailandesa guavas, three species in Kumagai guavas and three species in garlic passion fruit. This is the first report of a frugivorous fly infesting P. tenuifila. Individualization of the fruit samples was used to determine the co-infestation between Anastrepha spp., Ceratitis capitata and Neosilba spp. in each fruit. There was a fly/parasitoid association for Doryctobracon areolatus and Lopheucoila anastrephae with Anastrepha fraterculus in guavas. Infestation indices and emergence rate demonstrated that Tailandesa and Kumagai guavas are hosts capable of withstanding an infestation index ≥ 50 pupae/fruit and have an emergence rate ≥ 75%. The ability of some hosts to maintain and sustain the population of frugivorous flies at high levels may interfere with pest management.

SIMULATING OF FUTURE CLIMATE CONDITIONS ON THE EFFECT OF IRRIGATION ON SUGARCANE YIELD IN SOUTHERN BRAZIL

The objective of this study was to evaluate the technical and economic feasibility of installing central pivot irrigation systems in current days (Scenario A) and in two future scenarios, one with a 10% increase in rainfall (Scenario B1) and the other with 10% reduction in rainfall (Scenario B2). For both future scenarios, an increase of 2ºC in the global temperature and the concentration of atmospheric carbon dioxide (CO2) increasing to 528 ppm (parts per million) were considered. For the study, the recommendation for an area of clayey soil and with the sugarcane cycle was evaluated on three different planting dates: May 15, August 15 and November 15. The DSSAT/CANEGRO model was used, and under the current conditions, the simulations indicated greater yield for planting in May, both for rainfed and irrigated. For scenario B1, there was an increase in yield of 22% for rainfed and 33% for irrigated. In addition, irrigation provided yield gains in the two future scenarios of 13% and 14% for B1 and B2, respectively. Based on the results obtained, central pivot irrigation proved economically viable in the simulated climatic conditions. Therefore, the increase in sugarcane production provided by irrigation in agronomic management was sufficient to make investment in the region in question feasible. It is suggested to repeat the study in other regions, since the existing synergy between the factors that define agricultural yield can change the decision making about the implantation of irrigation systems in the production environment.

A NEW SPECIES OF ERIOPHYID MITE FROM BRAZIL (Acari: Trombidiformes)

On a survey of plant mites in the State of São Paulo, Brazil, a vagrant eriophyid mite on the leaves of Luffa cylindrica was collected and proved to be new for Science. It is herein described and figured.

SOIL FERTILITY: CHALLENGES TO SOYBEAN (𝘎𝘭𝘺𝘤𝘪𝘯𝘦 𝘮𝘢𝘹 L.) PRODUCTIVITY IN CONSOLIDATED NO-TILLAGE SYSTEM

The objective was to evaluate the relationship of soil fertility in areas with productivities gradients of soybean managed under no-tillage system (NT) in Western Santa Catarina, Brazil, and the interaction of this fertility with the physical and biological attributes of the soil. Areas with NT of High (NTH), Medium (NTM) and Low (NTL) soybean productivity were selected during the agricultural years 2016/2017 and 2017/2018. In each system, a sampling grid of 3 × 3 points, positioned 30 m apart, was used. Univariate analysis of the data showed no difference between the systems. However, principal component analysis helped identify the attributes that can affect productivity. Redundancy analysis identified the influence of biological attributes on some soil nutrients. The explanation for higher soybean productivities in NT system should not consider just the chemical fertility of the soil, but a holistic approach to fertility.

POTENTIAL OF MAIZE, MILLET AND RATTLEBOX TO BREAK THE CYCLE OF 𝘚𝘱𝘰𝘥𝘰𝘱𝘵𝘦𝘳𝘢 𝘦𝘳𝘪𝘥𝘢𝘯𝘪𝘢 (CRAMER) (LEPIDOPTERA: NOCTUIDAE)

This study evaluated the effect of different crops grown during soybean offseason on the development and reproduction of Spodoptera eridania (Cramer). The experiment was conducted in laboratory at 25°C±1°C, relative air humidity of 70%±10% and a 12h photophase. The plants evaluated were cotton (FMT 701), sunflower (Embrapa 122-V2000), rattlebox (Crotalaria spectabilis Roth), corn (Dekalb 370) and millet (DR-300). The less suitable hosts for the survival of S. eridania were rattlebox, corn and millet. Only cotton and sunflower the specie completed its development (egg to adult). Corn, millet and rattlebox were the crops that most affected the performance of S. eridania, and therefore they could potentially be used in the soybean offseason period to interrupt the life cycle of this species, and thus reduce population incidence during soybean season.