Sunflower Farm

Sunflower’s consistent yield and drought-tolerance make it an attractive crop for SA’s dryland regions. It also has a relatively long planting window. Nonetheless, care should be taken to plant at the optimal time, cautions Dr Safiah Ma’Ali, senior researcher at ARC-Grain Crops Institute.

Over the years, sunflower has come to be considered an ideal low-input crop for South Africa’s marginal cropping conditions.

It is currently the country’s third-largest grain crop after maize and wheat, and is primarily used for the manufacture of oil for human consumption and oilcake for animal feed.

Sunflower produces relatively consistent yield even under adverse weather conditions.

The plants are particularly efficient at extracting water from the soil, especially sandy loam.

This is underscored by the surprisingly high yields realised compared with those of other crops during the 2014/2015 drought.

Unlike other grain crops, sunflower has a relatively long planting window from early November to late January. But this can be misleading. It is important to choose the planting time carefully to ensure a good plant population.

The Agricultural Reseach Council’s Grain Crops Institute in Potchefstroom (ARC-GCI) has been conducting research on sunflower planting dates since 2007, which has demonstrated the importance of planting date for producing maximum yield.

Growth Stages
To better understand the effect of planting date on yield, each of the growth stages must be carefully considered: planting to floral initiation (GS1); floral initiation to bloom (GS2); and bloom to physiological maturity (GS3).

The yield components of sunflower, namely heads per hectare, number of seeds per head and weight per seed, are determined during these phases.

GS1: planting to floral initiation
This begins when the seed is planted and ends when the floral parts of the sunflower are initiated. Floral initiation cannot be observed directly; it occurs between the 10-leaf and 14-leaf stages. In GS1, sunflower is at its most delicate and is highly sensitive to stress. Fortunately, stress occurring during this period has little effect on yield. The plant must remain alive only to maintain the yield component of heads/ha.

GS2: floral initiation to bloom
Although the start of this growth stage is not readily recognisable, it determines the final yield. The floral parts, which later become the harvested seeds, are formed during this phase. After the seeds are initiated, they expand to form the visible bud and, eventually, the sunflower head, which blooms and thus completes GS2.

The head size, or the number of seeds/head, is established during this stage. Any stress that limits growth rate during GS2 will result in a reduced number of seeds/head.

Drought stress during this stage reduces yield more than at any other phase of sunflower development.

GS3: bloom to physiological maturity
The final stage of development begins when flowering is completed and the plant reaches physiological maturity.

During GS3, seed size and weight are determined. As physiological maturity approaches, the sunflower can utilise progressively lower temperatures for seed growth, while also becoming increasingly drought-tolerant.

Stress during GS3 can reduce yield, but not usually to the same extent as the reduction during GS2, as seed weight is a relatively smaller contributor to yield than seed number under most conditions.

Moisture
Ultimately, soil moisture, the most limiting yield factor, determines the planting date. Obviously, it’s difficult to predict when and how much rain will be received, so long-term averages are important (see Figure 1).

Figure 1: Rainfall (mm) and sunflower seed yield (t/ha) from the 2007/2008 to 2015/2016 growing season in Potchefstroom.

It should be pointed out, however, that such data and yield are often unrelated. Even moderate amounts of rainfall received at critical stages of growth, such as the first phase of GS2, can stimulate yield potential.

All the same, the graph clearly indicates that yield generally decreases the later the crop is planted after the period of maximum rainfall.

Another factor affecting sunflower stand is poor germination due to excessive heat at the time of planting.

Sunflower sometimes has to be planted in January or even early February, and temperatures 2017during this period often reach 32°C to 35°C.

Temperatures in this range are not ideal for sunflower seed germination. Even when seeds germinate, high temperatures may cause them to wither and die.

In addition, topsoil tends to dry out rapidly in the heat, so farmers are forced to plant the seeds slightly deeper when soil moisture content is higher. This can be risky, however; a single hard shower of rain after planting can cause a thick crust to form and the seedlings will be unlikely to emerge.

The right time
To reiterate, it’s important for producers to choose the planting time carefully and ensure a good plant population.

For the past 10 cropping seasons, seed yield from 38 national sunflower cultivar trials planted by ARC-GCI in Potchefstroom has been evaluated under three separate planting dates (1 to 30 November, 1 to 30 December and 1 to 30 January).

The results indicated that seed yield was reduced by approximately 0,21t/ ha for each 30-day delay in planting after November (see Figure 2).

Figure 2: Sunflower seed yield (t/ha) at different planting dates in 39 trials in Potchefstroom during the 2007 to 2016 growing season.

The yield probability percentages for the different planting dates were subsequently calculated at different yield threshold ranges (0,5t/ha to 3t/ ha).

The results showed that the probability of obtaining higher yield under a specific yield threshold (>1,2t/ha) was lower when the crop was planted after December (see Figure 3).

Figure 3: Probability (%) of exceeding different yield potentials for three planting dates in 38 sunflower trials in Potchefstroom (2007 to 2016 growing season).

Put another way, sunflower planted later in the season, especially during January, will have a lower yield potential. A farmer planning to plant sunflower as a main crop should consider planting during November and no later than the end of December in order to reach the target yield of more than 2t/ha.

Agribusiness Information

85 COMMENTS

  1. Accused in the past of embezzling players' funds, OddsPoker is still operating through its Antigua license, but that doesn't make it a safe place to play. To comply with anti-money laundering legislation, legal US poker sites are not allowed to accept new players unless they provide Personal Identifiable Information (PII). Playing poker can sometimes take hours and hours. Some games can be quick when played online, but land casino games are very rarely fast. Imagine this…You get stuck into a game at noon and, suddenly, it’s 8pm in the evening. Where did the time go? It is easy to get lost while playing poker, and along with lost time, you will probably feel exhaustion.  The poker sites we recommend offer a particularly large selection of game variants and tournament formats, and you can usually play all the games that are available for real money with play money. Here you can not only play Texas Hold’em for free, but also engage in many other lesser-known games such as Omaha, Stud, Triple Draw 2-7, Razz, and HORSE. Even action-packed, turbo variants of poker like Snap or Zoom are also available as free games. https://ruskillfish.ru/forum/profile/teradoll2146680/ In 2011, Tilman Fertitta bought the run-down Trump Marina casino in Atlantic City for $38 million, renamed it the Golden Nugget and put $150 million into renovations. Gaming revenue is up 50% from a year ago. Mars Casino Dracula Fun bitcoin casino london So, the BestCryptoCasino.today platform based on AI determines how gambling sites meet certain parameters with an accuracy of up to 92%. Based on its assessment, we have compiled a list of the TOP representatives of bitcoin casinos: Bitcoin casino reviews represent an indispensible guide that can help you explore the world of bitcoin gambling safely. Benefit from the experiences of others who play on bitcoin casinos and choose the one that suits your needs and preferences. The first casino on our list is the Dragonara Casino found in the heart of the Mediterranean, on the island of Malta. Owned and operated by Dragonara Gaming Limited, it features 300 slot machine games, 15 dice tables, a VIP lounge for high rollers and a poker room. The casino’s exterior speaks luxury and class, while the interior gives you the Mediterranean view when you step into it.

  2. Right here on Onlineroulette.org! Just find a roulette game you want to try, like European roulette or American roulette and give it a go. When you’re ready to play for real money, one of our top-rated roulette sites will offer you the best bonuses & most exciting roulette games. Some online roulette casinos, like Bovada and CafeCasino, offer free practice roulette games. You won’t be eligible to win real money when playing practice roulette, but these virtual games do offer a way to learn the rules of the game. Even more important, free roulette games allow you to try out a casino’s gaming software before you commit to the platform. It is a Federal offense for persons physically located outside of Michigan to engage in Internet wagering through this website. Our Free Roulette game serves to virtually transport you to land-based casinos that are found in some of the world’s most well-known gambling meccas across the world. The online casino game found on this particular page is none other than European Roulette – one of the world’s most popular variants of the game. Much of its popularity stems from the fact that this game not only has simple rules to implement but also that this version of Online Roulette has a much lower house edge than its American cousin. https://islam.ng/community/profile/felicitashague2/ That just about wraps everything up in this review of the best casino apps for iPhone. As an Apple user, you have a lot of great options available to you. Furthermore, as a British player, you can enjoy some of the best and most well-regulated operators worldwide on iPhones. Whether you’re looking to bet from an iPhone, Android, or Google phone, there will be mobile sports betting available to you on any operating systems. If you’re wondering what the best gambling sites for 18 and up bettors are that feature mobile capabilities, look no further. Read our mobile sports betting guide and discover the ways 18+ bettors can wager on their favorite sports. What Causes an Addiction to Gambling? Many factors can contribute to a gambling addiction, including desperation for money, the desire to experience thrills and highs, the social status associated with being a successful gambler, and the entertaining atmosphere of the mainstream gambling scene.

LEAVE A REPLY

Please enter your comment!
Please enter your name here