28 Aug 2019
Post bloom Fruit Drop

Plant hormone inhibitors for reducing postbloom fruit drop (pfd) of citrus

Hiu-Ling Liao, Huiqin Chen & Kuang-Ren Chung
University of Florida, IFAS Citrus Research and Education Center

Postbloom fruit drop (PFD) of citrus is caused by the fungus Colletotrichum acutatum. The fungus infects flower petals causing brownish lesions that result in young fruit drop, leaf distortion, and formation of persistent calyces (commonly called ‘buttons’) after the fruitlet drops. Previous studies suggested that an imbalance of plant growth regulators such as auxin, ethylene, and jasmonic acid in C. acutatum-infected flowers, may contribute to young fruit drop.

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28 Aug 2019
Satsuma

Girdling increases carbohydrate availability and fruit-set in citrus cultivars irrespective of parthenocarpic ability

F. Rivas, M. Juan, V.Almela, M. Agusti
Departamento de Producción Vegetal, Cátedra de Citricultura, Universidad Politécnica de Valencia.
E. Alos
Departamento de Citricultura, Instituto Valenciano de Investigaciones Agrarias. Valencia, Spain
Y. Erner
Department of Fruit Tree Sciences. Israel

The effects of girdling performed at various dates were evaluated during two consecutive years in high- and lowbearing commercial orchards of ‘Fortune’ mandarin and ‘Clausellina’ Satsuma mandarin. The time-dependent response was evaluated through fruitlet abscission, final fruit-set and yield as related to carbohydrate contents in developing fruitlets. A few days after treatment, girdling increased the soluble sugars content (SSC) in fruitlets, reduced the daily fruit drop, and thereby diminished abscission. Application of girdling to low-bearing ‘Fortune’ mandarin orchards was most effective 15 d before anthesis (DBA) and 35 d after anthesis (DAA). It increased yield by 125%. In high-bearing orchards, the best results were achieved by girdling 35 DAA, which increased yield by 28%.

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28 Aug 2019
Cover crops

Cover crops for citrus

Sarah Strauss, Davie Kadyampakeni, Ramdas Kanissery, Tara Wade, Lauren Diepenbrock and Juanita Popenoe
Citrus Industry

Cover crops are specific crops not intended for sale but for soil improvement and sustainability. They are increasingly common in the agricultural fields of the Midwest and other grain-producing regions because of the wide range of benefits not just for the soil, but also the cash crop. In those systems, cover crops improve water and nutrient retention, promote microbial activity, reduce weed growth and insect pests, and improve plant growth. Similar impacts have been found in tree crops like apples and peaches, where cover crops are planted in row middles.

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28 Aug 2019
Citrus

Use of the Cover Crop Weed Index to Evaluate Weed Suppression by Cover Crops in Organic Citrus Orchards

Jose Linares, Johannes Scholberg, and Kenneth Boote
University of Florida, Agronomy Department
Carlene A. Chase and James J. Ferguson
University of Florida, Horticultural Sciences Department
Robert McSorley
University of Florida, Entomology and Nematology Department

Citrus is one of the most important crops in Florida. During the past decade, increased international competition and urban development, diseases, and more stringent environmental regulations have greatly affected the citrus industry. Citrus growers transitioning to organic production may benefit from premium prices, but they also face many challenges, including development of effective weed management strategies. Cover crops (CC) may constitute an environmentally sound alternative for improved weed management in organic systems.

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31 Jul 2019
Orange Juice

New study on citrus greening disease

https://www.sciencedaily.com

Orange juice is a staple on many breakfast tables, but the future availability of citrus products is threatened by the global spread of huanglongbing (HLB), also known as citrus greening disease.

Knowing which environmental conditions are suitable for disease transmission and where those conditions occur is vital for crop management. A new study published by researchers at Virginia Tech with a team of international researchers in Journal of Applied Ecology investigates the thermal suitability for transmission of citrus greening with implications for surveillance and prevention.

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31 Jul 2019
Citrus Improvement

Quality and Quantity Improvement of Citrus: Role of Plant Growth Regulators

Harsimrat K. Bons, H.S. Rattanpal
Department of Fruit Science, Punjab Agricultural University, Ludhiana, Punjab, India.
Nirmaljit Kaur
Department of Botany, Punjab Agricultural University, Ludhiana, India.

Citrus is one of the most important fruit tree species in the world, as the fruits are a valuable source of nutrients, vitamins and other antioxidant compounds. The citrus productivity depends on various factors, among these the plant growth regulators holds a prime position. The use of plant growth regulators has become an important component in the field of citriculture because of the wide range of potential roles they play in increasing the productivity of crop per unit area. The plant growth regulating compounds actively regulate the growth and development by regulation of the endogenous processes and there exogenous applications have been exploited for modifying the growth response.

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31 Jul 2019
Citrus Weeds

Controlling Difficult Weeds in Citrus Groves

Ramdas Kanissery, Camille McAvoy and Mongi Zekri
http://citrusindustry.net

Some weeds are more difficult to manage in the production system than others due to their ability to grow in an available niche. If given a chance to establish, Guinea grass and goatweed can be the two most difficult weeds to manage. This is not just because they both are prolific seed producers, but also due to their inherent biological ability to survive grove conditions.

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31 Jul 2019
Citrus greening

Citrus greening research in Florida yields new tool in battle against disease

Paul Brinkmann
https://www.upi.com

ORLANDO, Fla., May 2 (UPI) — A new machine being developed in Florida might provide another weapon against the spread of citrus greening disease, which has decimated crops worldwide.

The automated system would help detect and count the tiny pin-sized bugs that carry the disease, also called Huanglongbing or HLB. It would then give farmers a map of where the bugs have shown up in their fields, allowing for targeted precise insecticide spraying.

The device, known as an Automated Psyllid Detection System, is under development at University of Florida’s agricultural research station in Immokalee.

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26 Jun 2019
Pink Apple

The effects of organic and inorganic mulches on the yield and fruit quality of ‘Cripps’ Pink’ apple trees

Van der Merwe, Johannes Dawid Prins 
Thesis (MScAgric)–Stellenbosch University, 2012.
http://hdl.handle.net/10019.1/71950

Limited research is available on the effect of mulches on established orchards. Most of the information available stems from research conducted in newly planted orchards or on annual crops such as green peppers and strawberries under greenhouse conditions. To increase the current knowledge on the effect of mulches in established orchards, two field trials were conducted on 14 year old „Cripps‟ Pink‟ orchards. The one trial concentrated on the influence of mulches on the root environment and the other trial on the effect of mulches on growth, yield and fruit quality.

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26 Jun 2019
Soil Surface

Effects of soil surface management practices on soil and tree parameters in a ‘Cripps Pink’/M7 apple orchard 2. Tree performance and root distribution

John Wooldridge, Johan Fourie & Marlise E Joubert
https://www.tandfonline.com

There are around 22 000 ha of commercial apple orchards in South Africa. Of these, 70% are located in the upland areas of the Western Cape. The apple industry exports c. 40% of its production and supports an on-farm labour force of 27 800 (Hortgro 2012. Apple producers are currently adjusting their production techniques to meet increasing consumer demands for organic over conventionally produced fruit.

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