We continue with Maseches Ma'asros, chapter 1, mishnah 2. As we learned in the introduction, the earliest point at which food can be tithed and have the tithing take effect is once the food has been detached from the ground and is minimally fit to be eaten. That point - when the fruit has just reached the threshold of edibility, meaning it could be eaten in a pinch - is called onas hama'asros, the season of tithes. This is the earliest moment at which tithing takes effect, although, as was mentioned, one should not actually tithe until after gemar melachah, once the fruit has fully ripened and its processing is complete.
The mishnah asks: "Me'eimasai haperos chayavos b'ma'asros?" - from what point does the obligation of ma'aser apply, such that if a person tithes, the tithing takes effect and the berachah is not said in vain. From here on the mishnah lists a long series of types of produce, noting for each one the moment at which it reaches the threshold of edibility.
One clarification is in order first: nowadays we are fussy and pampered, and it would never occur to us to eat fruits and vegetables at the early stages described here. In the time of the Mishnah, however, conditions were not nearly so comfortable, and people sometimes ate even unripe fruit because they had no better option. As long as the fruit is not harmful, and it can be swallowed and provide some nutritional value, it is considered fit to eat - and at that point it has reached onas hama'asros.
The order of the fruits in the mishnah (following the translations of the Yad Avraham edition):
"HaTe'einim - mishe'yavchilu" - from the time the figs begin to ripen. The term "yavchilu" is specific to the ripening of the fig, and it means that their tips begin to turn white and light. Observation of figs shows that they are green at first, then turn red, and finally turn a silvery purple; in any case, once the tip takes on a whitish tone, that is the threshold of edibility.
"Ha'anavim veha'ovshim - mishehiv'ishu" - the ovshim are an inferior species of grape. "Hiv'ishu" is often understood as an expression of spoiling or rotting, but here it means that the fruit takes on a pale hue and becomes somewhat translucent, so that the seeds inside can be seen through the skin. At this stage they are sufficiently ripe.
"Ha'og vehatusim... vechol ha'adumim - mishe'ya'adimu" - og is translated as sumac, as it was translated in Maseches Kilayim as well. Tusim are translated as mulberries, even though in modern Hebrew the word "tut" is used for all sorts of berries. And so too all red fruits: from the time they begin to redden, they are considered edible at need, and thereby they have reached onas hama'asros.
"Harimonim - mishe'yimasu" - from the time they become soft and can be squashed between one's hands. At that stage they are soft enough to be considered food, and they have reached onas hama'asros.
"Hatemarim - mishe'yatilu se'or" - se'or is the fermenting agent used as a leavening for dough (such as the leftover leavened dough of yesterday used for today's baking, or the yeast we use today). The meaning here is that from the time the dates begin to swell slightly and develop cracks - and there are various versions of exactly what is being referred to - they have reached onas hama'asros.
"HaParsekim - mishe'yatilu gidim" - parsekim are peaches, and from the time thin veins begin to appear on their surface, a sort of vein structure developing within them, they have reached onas hama'asros.
"Egozin - mishe'ya'asu megurah" - literally: from the time the nut develops a storage chamber. A nut has flesh that looks like a brain, and the shell around it is like a skull. As long as the nut is not ripe, the "brain" is attached to the "skull"; once it ripens, it draws inward and a compartment of its own is formed, and it rattles around inside. From the time it has its own compartment and is no longer attached to the shell, it is considered ripe enough to eat, and it has reached onas hama'asros.
The dispute of Rabbi Yehudah:
"Rabbi Yehudah omer: Egozim ushekedim - mishe'ya'asu kelipah" - Rabbi Yehudah disagrees with the first Tanna and holds that nuts and almonds are not considered fit to eat until they form a kelipah, a coating around the nut, which is a much later stage. The halachah, however, does not follow him; rather, the halachah is that once the megurah has formed - that is, once the nut has loosened somewhat inside its shell - it has already reached onas hama'asros.
In summary: in this mishnah we learned the principle that produce becomes obligated in ma'asros once it reaches onas hama'asros, the point of the threshold of edibility, along with the specific signs for each species: figs from when they begin to ripen, grapes and ovshim from when they turn pale, sumac and mulberries and all red fruits from when they redden, pomegranates from when they soften, dates from when they begin to swell, peaches from when they form veins, and nuts from when they form a megurah - as well as the dispute of Rabbi Yehudah regarding nuts and almonds, in which the halachah does not follow him.